1. Field of the Invention
The present invention relates to continuous, random dyeing apparatus for carpet or the like and, more particularly, to apparatus for continuously dispensing a liquid onto a moving web in an irregular and random pattern.
2. Description of the Prior Art
A recent trend in manufacturing tufted carpet involves finishing a single color carpet in such a way that although the single color remains the dominant base tone, additional color patterns are applied thereto. To be most effective, the color patterns should not appear in regularly recurring portions but should form a certain unified irregularity or randomness which is aesthetically pleasing to the eye. This type of coloring has further achieved significance in other fabrics, as for example decorative fabric materials. Accordingly, although the remaining discussion will be directed to carpets, it will be appreciated by those skilled in the art that it is equally applicable to any textile material and to moving webs generally.
A number of methods have been proposed for the continuous, random application of color to carpet. In order for any such method to be economically feasible, the application speed must be adequate and the application of the dye must be easily controlled in any number of various patterns. The methods of application and control must be relatively simple as well as being easy to maintain. However, none of the methods proposed heretofore have satisfied all of these requirements.
One method of producing a random pattern on carpet has been commonly designatd as "space dyeing". In this method, the yarn is dyed various colors and shades of colors along its length. This dyed yarn is then tufted into the carpet. The disadvantages of this method are that it is costly to space dye the yarn and, once the yarn is space dyed, there is only a limited control of the random pattern which is obtainable once the tufting of the carpet begins.
Another process, referred to as "Tak" dyeing, for applying dyes to carpet in random patterns is disclosed in U.S. Pat. No. 3,731,503. According to this patent, an oscillating wiper blade channels dye into streams which fall towards the moving carpet, which streams are divided by a moving wire member supported on a circular band. Some of the dye falls and is distributed on the teeth of an adjustable comb-like device, from which the dye falls to the carpet in an irregular pattern. The remaining dye falls directly onto the carpet after being divided by the circulating band. The problem with this process is that the machinery involved is complex in nature. This leads to difficulty in pattern control as well as a substantial expense to purchase and maintain the machinery.
Jet printing is another method of applying random patterns to carpet. According to this method, an array of spray nozzles, which spray different colors, are moved from place to place above a moving carpet. In addition, the nozzles are controlled as to whether they are open or closed. The patterns are programmed via an electronic device. The disadvantages associated with this method are that the equipment is expensive, the nozzles become clogged, and maintenance costs of the electronic and mechanical equipment is high.
A process referred to as rotary screen printing is also used to apply dye to carpet in a random pattern. In this process, a hollow rotary drum is used which has small holes etched through the surface thereof to the hollow portion, in any desired pattern. Dye is forced through these holes which are in contact with the carpet surface as the drum rotates. The main disadvantage here is that the resultant pattern is very rigid. In addition, the cost of the etched drums and the equipment needed to run them is expensive.